It is reported in many articles that a β-hydroxyester is prepared by reacting an epoxide with carbon monoxide and an alcohol such as methanol, etc. in the presence of a cobalt carbonyl compound such as dicobaltoctacarbonyl complex, etc. (this reaction is called “hydroesterification” hereinafter.), but this reaction lacks in selectivity, is poor in yield and requires high pressure (140 atm) (see for example, Journal of the Nippon Kagakukai, Vol. 5, p 635 (1979)).
Furthermore, it is described in European Patent Publication A 577206 that in order to make this reaction effectively proceed, hydroxypyridines are used as co-catalyst. It is described in US Patent Publication A 2002/0099245 that imidazole, pyrimidine, pyrazine, pyrrole and so on are effective as co-catalyst in this reaction. It is also reported that when an inorganic base is used as co-catalyst, the reaction proceeds at lesser carbon monoxide pressure, different from in the co-catalyst mentioned above (see Synthesis, p 492, 1986 and Japanese Patent Publication A 57-183749).